Hey there!
I'm DJAutismo, otherwise known as the author of this guide. I'm currently unranked at the moment, but I consider myself to be at least an above average Jax main, plus I heavily enjoy playing him, so I thought I'd write a guide for him. While this guide might not be as in-depth as other Jax guides, it should be a good fit for beginner Jax players who simply want to jump in and have some fun with him.
Enjoy!

P.S. If the title isn't clear, this guide is made for Jax in a Jungle role only! I haven't really played Jax toplane enough to really write a guide on him.

Before you consider picking up Jax, you should ask yourself some questions:
Do you enjoy any of the following:
Spins
Stuns
Having 3 fingers
Wielding a lamppost (and imagining if you had a real weapon)
Reaching max attack speed (and possibly exceeding it depending on runes)
Being one of the most badass champions in the League
Hashinshin (when he's not complaining about Riven or Fiora being broken)
Being pretty simple, fun, yet effective to play

If you answered yes to most of these questions, then Jax may be a good fit for you!

Pros:

Good dueling potential
Can seriously snowball if given enough ganks
Can auto attack reset with his W
Built in escape with his Q
Can become pretty tanky with his ult

Cons:

Can be seriously shut down with CC
If his stun doesn't land it can mean a quick death
A bit slow even with boots
Might have some trouble initiating teamfights

	Relentless Assault (Passive) Jax gains bonus attack speed for 2.5 seconds every time he lands a basic attack, stacking up to 8 times. This falls off one stack at a time. Simply put, as you attack, you gain attack speed. This can be a real help when clearing jungle camps, or it can give you the necessary edge to outduel an opponent if need be.
	Leap Strike (Q) Jax leaps to targeted enemy while dealing physical damage to the target. This, for me is Jax's main bread and butter. It can be used to initiate a fight, get out of one by jumping on an ally champion, ward, plant, etc., or finish off an enemy with maximum satisfaction. On top of that, it can be combined with your W and/or E to deal extra magic damage and/or stun your opponent when you jump on them. All in all, it's a very versatile ability.
	Empower (W) Jax's next basic attack or Leap Strike within 10 seconds deals bonus magic damage. In addition to giving you some extra damage, this ability also resets your auto attack timer, meaning you can use it just after a basic attack to get a quick hit.It also makes your next basic attack gain a bit of range which can certainly help with ganks.
	Counter Strike (E) When activated the first time Jax will block all incoming auto attacks for 2 seconds as well as will take 25% reduced damage from all area of effect abilities. At the end of the duration or when reactivated Jax stuns nearby enemies for 1 second and deals physical damage to them, increased by 20% for each attack dodged, up to a 100% increase. This ability produces nearly as much toxicity as the game in question! But it can be very helpful in ganks, teamfights, 1v1s-the possibilities are endless. Honestly, once you hit lategame with Jax, if you stun an opponent with this, it's pretty much over for them. In addition, it can also to help you heal up in jungle, and will give you some free stacks of Guinsoo's and your passive.
	Grandmaster's Might (R) Passive: Every 3rd basic basic attack within 2.5 seconds of each other will deal bonus magic damage. Active: Jax gains bonus armor (scaling with AD) and bonus magic resist (scaling with AP) for 8 seconds. The active on Jax's ult isn't as flashy as a lot of the other ults in the game, but it gives a pretty good amount of defense and can temporarily make Jax pretty tanky in a teamfight. The passive, however, is certainly nothing to scoff at. One possible trick with it is to get 2 basic attacks (which might actually be a bit difficult at higher attack speeds), leap on an enemy to hit them with the bonus magic from the ult passive, then immediately use your W to hit them with a reset auto attack. This can do a nice burst of immediate damage, as well as scare off an enemy.

Hey there!

If you're reading this, then you've either just scrolled through this guide and made it to the bottom, or you've actually read this guide to the end. Either way, I hope you enjoyed it, and I hope I've made a Jax main out of you.

-DJAutismo